Optical film laminate, and polarizing plate laminate and display using the same

Abstract

The present invention provides an optical film laminate capable of suppressing reduction in viewability and occurrence of blurring of a screen while a display is on, and making a white or light-colored peripheral material of the display seamless. This optical film laminate is an optical film laminate for a display and used while laminated directly or indirectly on a polarizing plate (A). The display includes a display panel device, the polarizing plate (A) is laminated directly or via another layer (b) on the viewing side from the display panel device, a reflective polarizer layer and a diffusion element layer are laminated directly or via another layer (a), the diffusion element layer is disposed on the viewing side from the reflective polarizer layer, the optical film laminate is laminated directly or via another layer (c) on the viewing side from the polarizing plate (A), the optical film laminate is disposed such that the transmission axis of the polarizing plate (A) and the transmission axis of the reflective polarizer layer have a relationship of 0±30° or 180±30°, and the reflective polarizer layer reflects polarized light orthogonal to the transmission axis of the polarizing plate (A).

Description

[Technical Field]

[0001] The present invention relates to an optical film laminate, and a polarizing plate laminate and a display using the same. [Background technology]

[0002] 2. Description of the Related Art Conventional thin displays such as liquid crystal displays and organic EL displays have become widespread and are used in a variety of ways. In recent years, there has been progress in the development of products that use thin displays for part of the display system of the instrument cluster panel, which is the main part of the instrument panel in automobiles, or the entire panel, or that use thin displays for the center information display (CID). In order to prevent external reflections, automobile interiors are primarily black (dark colors), but from the perspective of design, seamlessness (neutral gray) is being used to make the boundary between the front panel, which is the outermost surface of the image display unit of the flat panel display, and the material around the front panel (such as the interior), less visible and to make it difficult to recognize the presence of the front panel.For automobile interiors with a black color scheme, seamlessness is being achieved by correcting the front panel of the flat panel display with black to make the boundary of the flat panel display less noticeable (Patent Document 1).

[0003] Furthermore, there are an increasing number of cases where flat-panel displays are embedded in various home appliances other than televisions and monitors, and it is expected that in the future there will be an increasing number of cases where flat-panel displays are embedded in furniture, and in the walls, floors, ceilings, etc. of buildings. Home appliances, furniture, and the walls, floors, ceilings, etc. of buildings are not limited to black (dark) color schemes, and many designs now feature white or light colors. Furthermore, with the advancement of autonomous driving technology, various considerations are being made regarding how to utilize the interior space of automobiles. One of the considerations is that as the proportion of people driving decreases, the interior space of a car may become like a living room in a house, and therefore the use of light colors such as white or light colors for the interior colors of cars, similar to the walls, floors, and ceilings of a house, is being considered. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-265133 Summary of the Invention [Problem to be solved by the invention]

[0005] The seamless display proposed in Patent Document 1 involves adjusting the color of the front panel of the flat panel display with a black pigment or dye, which reduces the transmittance of light emitted from the flat panel display and reduces visibility when the display is turned on. For this reason, measures such as increasing the backlight output of the display must be taken to ensure visibility.

[0006] Furthermore, when embedding or placing an LCD or OLED display in an environment using white or light colors in a car or home, the front panel surface of these conventional displays is black when turned off, making it difficult to achieve a seamless look with the surrounding materials. As with the invention of Patent Document 1, adjusting the color of the front panel with a white pigment or dye, as with the seamless look of black, reduces the transmittance of light emitted from the display, resulting in poor visibility when the display is turned on. Additionally, whitening increases the diffusion and reflectivity of light within the display, resulting in blurred images.

[0007] Therefore, an object of the present invention is to provide an optical film laminate that can suppress a decrease in visibility and the occurrence of screen blur when the display is turned on, and can be made seamless with surrounding materials of the display that use white or light colors. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention provides an optical film laminate that includes a reflective polarizer layer and a diffusion element layer, and is used in a display. The present invention (1) is An optical film laminate for a display, which is used by being laminated directly or indirectly with a polarizing plate (A), the display includes a display panel device; the polarizing plate (A) is laminated on the viewing side of the display panel device directly or via another layer (b), The optical film laminate includes a reflective polarizer layer and a diffusion element layer laminated together directly or via another layer (a), the diffusion element layer is disposed on the viewing side of the reflective polarizer layer, the optical film laminate is laminated on the viewing side of the polarizing plate (A) directly or via another layer (c), the optical film laminate is arranged so that the relationship between the transmission axis of the polarizing plate (A) and the transmission axis of the reflective polarizer layer is 0±30° or 180±30°, The reflective polarizer layer is an optical film laminate characterized by reflecting polarized light perpendicular to the transmission axis of the polarizing plate (A). The present invention (2) is the reflective polarizer layer includes a first polymer layer and a second polymer layer; The optical film laminate of the invention (1) is characterized in that either the first polymer layer or the second polymer layer is a naphthalate-based polymer. The present invention (3) is The optical film laminate of invention (1) or (2) is characterized in that the diffusion element layer is any one of a diffusion film having fine particles dispersed therein, a diffusion adhesive layer having fine particles dispersed therein, a nonwoven fabric, a diffusion film having an uneven surface, and a porous film. The present invention (4) is The optical film laminate of any one of the above inventions (1) to (3) is characterized in that the haze of the diffusion element layer is 40% or more and 95% or less, and the total light transmittance is 30% or more and 88% or less. The present invention (5) is The optical film laminate is transmitted light (T1) obtained by light from a C light source incident on the reflective polarizer layer side of the optical film laminate, passing through the optical film laminate and emitting on the diffusion element layer side of the optical film laminate, is measured in a 2° field of view in accordance with JIS Z8722:2009, and then the transmission Y value calculated using a C light source is 20 or more and 50 or less; The optical film laminate according to any one of inventions (1) to (4), wherein light from a C light source is incident on the diffusion element layer side of the optical film laminate, is reflected by a reflective polarizer of the optical film laminate, passes through the optical film laminate and exits on the diffusion element layer side, and reflected light (R1) is measured in a 2° field of view according to JIS Z8722:2009 standard, and the reflection Y value calculated using a C light source is 40 or more and 80 or less. The present invention (6) is The optical film laminate is the optical film laminate according to any one of the above inventions (1) to (5), characterized in that the whiteness WI value is 45 or more and 90 or less in a specular colorimetry (SCE) method using a D65 light source in accordance with ASTM E313-73 standard using a spectrophotometer. The present invention (7) is A polarizing plate laminate comprising the optical film laminate according to any one of the inventions (1) to (6) and the polarizing plate (A), the polarizing plate (A) is laminated to the reflective polarizer layer of the optical film laminate on the side opposite to the diffusion element layer of the optical film laminate, either directly or via another layer (d); The polarizing plate laminate is characterized in that the polarizing plate (A) and the reflective polarizer layer of the optical film laminate are arranged so that their transmission axes form an angle of 0±30° or 180±30°. The present invention (8) is The polarizing plate laminate is transmitted light (T2) obtained by transmitting light from a C light source incident on the polarizing plate side of the polarizing plate laminate, passing through the polarizing plate laminate, and emitting to the diffusion element layer side of the polarizing plate laminate is measured in a 2° field of view in accordance with JIS Z8722:2009, and then the transmission Y value calculated using a C light source is 15 or more and 40 or less; The polarizing plate laminate of invention (7) is characterized in that the light from a C light source incident on the diffusion element layer side of the polarizing plate laminate is reflected by a reflective polarizer of the polarizing plate laminate, passes through the polarizing plate laminate to the diffusion element layer side, and is reflected light (R2). After measuring the reflected light (R2) at a 2° field of view in accordance with JIS Z8722:2009, the reflection Y value calculated using a C light source is 40 or more and 80 or less. The present invention (9) is A display (D1) having a laminate structure including a display panel device, a polarizing plate (A) on the viewing side of the display panel device, and the optical film laminate according to any one of claims 1 to 6, the polarizing plate (A) is laminated on the viewing side of the display panel device directly or via another layer (b), the optical film laminate is laminated on the viewing side of the polarizing plate (A) directly or via another layer (a) such that the diffusion element layer is located on the viewing side of the reflective polarizer layer, the optical film laminate is disposed such that the transmission axis of the polarizing plate (A) and the transmission axis of the reflective polarizer layer form an angle of 0±30° or 180±30°; The display is characterized in that the reflective polarizer layer reflects polarized light perpendicular to the transmission axis of the polarizing plate (A). The present invention (10) is A display (D2) having a laminated structure including a display panel device and not including a polarizing plate on the viewing side of the display panel device, The display (D2) includes the polarizing plate laminate of the invention (7) or (8), the polarizing plate laminate is laminated on the viewing side of a display panel device directly or via another layer (c), The polarizing plate laminate is a display characterized in that the reflective polarizer layer of the polarizing plate laminate is disposed closer to the viewing side than the polarizing plate (A) of the polarizing plate laminate. [Effects of the Invention]

[0009] The present invention can provide an optical film laminate that can suppress a decrease in visibility and the occurrence of screen blur when the display is turned on, for a display that has a liquid crystal panel or an organic EL panel and a polarizing plate on the viewing side of the liquid crystal panel or the organic EL panel, and can be made seamless with peripheral materials of the display that use white or light colors. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram illustrating an example of the arrangement of the optical film laminate of the present invention and the laminate structure of a display when the display includes a polarizing plate (A). [Figure 2] FIG. 2 is a schematic diagram illustrating an example of the arrangement of the laminate structure of a polarizing plate laminate including the optical film laminate of the present invention and a display when the display does not include a polarizing plate (A). [Figure 3] FIG. 3 is a schematic diagram illustrating the measurement of the Y value of the optical film laminate of the present invention. [Figure 4] FIG. 4 is a schematic diagram illustrating the measurement of the Y value of the polarizing plate laminate of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] In the present invention, when a compound name is simply indicated, it is intended to include all of its isomers.

[0012] In the present invention, the display panel device refers to a driving panel for displaying images, such as a liquid crystal display panel, an organic EL panel, or a micro LED panel. In addition, in the present invention, the driving panel of a liquid crystal display panel refers to a panel including elements necessary for display, such as a liquid crystal cell, a backlight, and a color filter, and in the present invention, the display panel device includes a panel with or without a polarizing plate on the viewing side. Furthermore, a driving panel is something that controls the polarization of liquid crystals, such as a liquid crystal cell, to transmit or block light (open and close a shutter), or something that turns on and off the light emission of light-emitting elements, such as an organic EL panel or micro LED panel, to form an image.

[0013] A liquid crystal cell is a device in which liquid crystal molecules are sandwiched between two glass substrates incorporating transparent electrodes, or a device that further includes a color filter, but does not include a light source or optical films such as polarizing plates. An organic EL panel consists of a metal or other cathode, an electron injection layer, an electron transport layer, an emitting layer, a hole transport layer, a hole injection layer, an ITO or other anode, and a substrate such as a glass plate or a transparent plastic plate, but does not include optical films such as polarizing plates or color filters. Generally, organic EL displays do not use polarizing plates, but some have a polarizing plate on the viewing side of the organic EL panel to prevent internal reflections. A micro LED panel refers to a substrate on which micro LEDs are configured, and a polarizing plate may be used to prevent internal reflections, etc.

[0014] In the present invention, the viewing side refers to the side of the display that is closer to the viewer. Therefore, when referring to the viewing side of a display panel device, the viewing side refers to the direction of the viewer's side of the display panel device.

[0015] <<<Optical film laminate>>> The optical film laminate of the present invention includes a reflective polarizer layer and a diffusing element layer, which are laminated directly or via another layer (a).

[0016] The optical film laminate of the present invention is used by being laminated directly or indirectly with a polarizing plate (A) disposed facing the viewing side of a display panel device included in a display (see FIGS. 1 and 2).

[0017] The optical film laminate of the present invention is used so that the diffusion element layer of the optical film laminate is disposed closer to the viewer than the reflective polarizing element of the optical film laminate (FIG. 1 or 2).

[0018] The optical film laminate of the present invention is laminated on the viewing side of the polarizing plate (A) directly or via another layer (b) to the polarizing plate (A) (see FIGS. 1 and 2).

[0019] The optical film laminate of the present invention is arranged so that the relationship between the transmission axis of the polarizing plate (A) and the transmission axis of the reflective polarizer layer of the optical film laminate is 0±30° or 180±30°.

[0020] The reflective polarizer layer of the optical film laminate of the present invention reflects polarized light that is perpendicular to the transmission axis of the polarizing plate (A).

[0021] The thickness of the optical film laminate is not particularly limited as long as it does not impair the effects of the present invention, but it can be, for example, 10 to 200 μm, and from the viewpoint of thinning, it is preferably 10 to 150 μm, more preferably 15 to 100 μm.

[0022] <<Configuration of optical film laminate>> <Reflective polarizer layer> The reflective polarizer layer has a function of separating light emitted from a liquid crystal panel or an organic EL panel into transmitted polarized light and reflected polarized light. The reflective polarizer layer of the present invention is a layer that transmits linearly polarized light in one vibration direction and reflects linearly polarized light in at least one other vibration direction.

[0023] When the optical film laminate of the present invention described below is used in a display, the reflective polarizer layer according to the present invention is arranged so that the transmission axis of the reflective polarizer layer and the transmission axis of the polarizing plate (A) are in the direction of 0±30° or 180±30°. In this case, the reflective polarizer layer reflects polarized light that is perpendicular to the transmission axis of the polarizing plate (A). It is more effective when the transmission axis of the reflective polarizer layer and the transmission axis of the polarizing plate (A) are in the angle of 0° or 180°. However, as long as the angle between the transmission axis of the reflective polarizer layer and the transmission axis of the polarizing plate (A) is within the range of 0° or 180° to ±30°, seamlessness between the display and white or light-colored display peripheral components can be easily adjusted.

[0024] The reflective polarizer layer may be any known one, and is not particularly limited as long as it does not impair the effects of the present invention. For example, the reflective polarizer layer (1) may be formed by alternately laminating multiple layers of two types of resins (e.g., polyethylene naphthalate as a first polymer layer and polyethylene naphthalate copolymer as a second polymer layer) that have different refractive indices in the stretching direction when stretched by extrusion molding, and then stretching the resulting layers (specifically, DBEF manufactured by 3M, see JP-A-4-268505, etc.); The reflective polarizer layer (2) is a laminate of a cholesteric liquid crystal polymer layer and a quarter-wave plate, which separates light incident from the cholesteric liquid crystal polymer layer into two circularly polarized light beams in opposite directions, transmits one beam and reflects the other, and converts the transmitted circularly polarized light beam into linearly polarized light beams using the quarter-wave plate (specifically, Nitto Denko's Nipox and Merck's Transmax, see JP-A-11-231130, etc.); Examples of the reflective polarizer layer (3) include reflective grid polarizers such as metal grid reflective polarizers (see U.S. Pat. No. 6,288,840, etc.) that emit reflective polarized light even in the visible light region by microfabricating metal, films obtained by adding metal microparticles to a polymer matrix and stretching the film (see JP-A-8-184701, etc.), and resin films with a wire grid formed inside using metal nanowires (specifically, WGF manufactured by Asahi Kasei Corporation; see JP-A-2017-173832, etc.). Of these, the reflective polarizer layer (1) is preferably used because of its excellent productivity and processability. On the other hand, when heat resistance is required, the reflective polarizer layer (3) is preferably used.

[0025] Here, the reflective polarizer layer (1) includes at least a first polymer layer and a second polymer layer.

[0026] The materials for the first polymer layer and the second polymer layer are not particularly limited as long as they do not impair the effects of the present invention, but from the viewpoint of productivity, it is desirable that either the first polymer layer or the second polymer layer be a naphthalate-based polymer, which facilitates molecular orientation when the polymer is stretched. Alternatively, both the first polymer layer and the second polymer layer may be naphthalate-based polymers. Here, a naphthalate-based polymer refers to a polymer containing a naphthalate functional group in its molecular structure.

[0027] Naphthalate polymers can be obtained by polymerizing these naphthalate monomers. The naphthalate monomers that can be used to form the naphthalate polymers are not particularly limited as long as they do not impair the effects of the present invention, but examples include naphthalates such as 2,6-, 1,4-, 1,5-, 2,7-, and 2,3-naphthalene dicarboxylic acid and their esters.

[0028] Naphthalate monomers can be polymerized with diols, such as alkane glycols and cycloalkane glycols, to form polyesters, such as polyethylene naphthalate, a copolymer of 2,6-, 1,4-, 1,5-, 2,7-, and / or 2,3-naphthalene dicarboxylic acid and ethylene glycol.

[0029] It can also be a copolymer of 2,6-, 1,4-, 1,5-, 2,7-, or 2,3-naphthalene dicarboxylic acid, terephthalic acid, and ethylene glycol, commonly referred to as coPEN.

[0030] The thickness of the first polymer layer and the second polymer layer is not particularly limited. A plurality of layers each including a first polymer layer and a second polymer layer are further laminated and stretched to form a reflective polarizer layer of the desired thickness, making it difficult to measure the thickness of the first polymer layer and the second polymer layer in the reflective polarizer layer. Generally, up to about 100 layers of first polymer layers and second polymer layers are laminated. The thickness of the reflective polarizer layer can be 10 to 100 μm, and from the viewpoint of thinning, 10 to 50 μm is preferred, and 10 to 30 μm is more preferred.

[0031] The total light transmittance of the reflective polarizer layer is not particularly limited as long as it does not impair the effects of the present invention. The total light transmittance of the reflective polarizer layer can be, for example, 30% to 70%, preferably 40% to 60%. When the total light transmittance is within this range, high whiteness can be obtained without reducing the light emitted from the display. That is, a display can be obtained that has excellent visibility and can be seamless with surrounding materials of the display that use white or light colors.

[0032] The total light transmittance of the reflective polarizer layer can be measured by the method described in JIS K7361-1:1997 "Test method for total light transmittance of plastic transparent materials." However, because the light source of the measuring instrument is polarized to some extent, a measured value that is not affected by the polarization of the light source can be obtained by calculating the average value of a value measured at a predetermined position and a value measured at an position rotated 90° relative to the position of the measuring instrument, and therefore, in the present invention, the average value of these two total light transmittances is shown as the total light transmittance.

[0033] <Diffusion element layer> The diffusion element layer is a layer having a function of diffusing transmitted light. The diffusion element layer is not particularly limited as long as it does not impair the effects of the present invention.

[0034] The thickness of the diffusion element layer is not particularly limited as long as the effects of the present invention are not impaired, but it can be set to 1 to 100 μm, and preferably 15 to 50 μm.

[0035] The diffusion element layer is The diffusion element layer (1) is made of a material having light-transmitting properties (in the present invention, transparent or translucent properties), such as a pressure-sensitive adhesive, adhesive, resin, glass, or nonwoven fabric, in which fine particles are dispersed; The diffusion element layer (2) has an uneven structure formed by processing the surface of a light-transmitting material such as resin or glass; The diffusion element layer (3) is made of a light-transmitting material such as resin, glass, or nonwoven fabric, with a porous structure inside; The diffusion element layer (4) is made of a light-transmitting material such as resin, glass, or nonwoven fabric, and has a plurality of through holes or non-through holes extending from one surface to the other surface; The diffusion element layer (5) is formed by forming a plurality of regions (e.g., cylindrical regions) with different refractive indices inside a translucent resin; These can be used alone or in combination. Note that a certain layer (e.g., nonwoven fabric) may correspond to multiple diffusion element layers, such as the diffusion element layer (1) in which fine particles are dispersed and the diffusion element layer (3) and the diffusion element layer (4) made of nonwoven fabric.

[0036] The diffusion element layer (1) is made by dispersing fine particles with a different refractive index than the base material in a base material such as adhesive, glue, resin, glass, or nonwoven fabric. These can be combined appropriately taking into account the required light diffusion performance. Here, the light diffusion performance refers to the light transmittance and the light diffusion resulting from the difference in refractive index between the base material and the fine particles.

[0037] The amount of fine particles added can be selected appropriately, taking into account the required light diffusion performance, so long as the haze when made into a diffusion element layer is 40% or more and 95% or less, and the total light transmittance is 30% or more and 88% or less.As an example, the amount can be 10.0 to 50.0% by mass, where the entire diffusion element layer is 100% by mass.

[0038] Examples of the material for the base material of the diffusion element layer (1) include acrylic adhesives; silicone adhesives; urethane adhesives; rubber-based adhesives; epoxy adhesives; olefin adhesives; polycarbonate resins; (meth)acrylic resins; polystyrene resins; polyolefin resins; polyester resins such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, and terebutylene terephthalate; various types of glass; glass fiber nonwoven fabrics; polyolefin resin fiber nonwoven fabrics such as polypropylene fibers; and the like.

[0039] The material of the fine particles of the diffusion element layer (1) is not limited as long as it does not impair the effects of the present invention, and examples thereof include inorganic white pigments such as silica, calcium carbonate, aluminum hydroxide, magnesium hydroxide, clay, talc, and titanium dioxide; and fine particles of resins such as silicone resin, acrylic resin, polystyrene resin, styrene-acrylic copolymer resin, polyethylene resin, and epoxy resin, which have a refractive index different from that of the adhesive. These can be used alone or in combination.

[0040] The average particle size of the fine particles can be appropriately selected as long as the resulting diffusion element layer has a haze of 40% to 95% and a total light transmittance of 30% to 88%, and can be, for example, 0.1 to 50 μm. The average particle size of the fine particles can be measured using a particle counter.

[0041] The diffusion element layer (2) has an uneven structure formed by processing the surface of a light-transmitting material such as resin or glass.

[0042] The material of the diffusion element layer (2) is not particularly limited as long as it does not impair the effects of the present invention, but examples thereof include polycarbonate resin; acrylic resin; polystyrene resin; polyolefin resin; polyester resins such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, and terebutylene terephthalate; various types of glass, etc.

[0043] The uneven structure may have recesses and / or protrusions on the surface, and there are no particular limitations on the shape, size, number, distribution, distribution density, or distribution regularity.

[0044] Examples of the uneven structure include a groove structure having a semicircular, polygonal, or wave-shaped cross section, a concave dot structure having a hemispherical, conical, cylindrical, polygonal pyramidal, polygonal prism, lens-shaped, or a convex dot structure. These may be used alone or in combination.

[0045] The size of the uneven structure can be appropriately selected so long as the haze when formed into a diffusion element layer is 40% to 95% and the total light transmittance is 30% to 88%. As an example, when the uneven structure is a groove structure, the average width of the grooves can be 0.1 to 50 μm, and when the uneven structure is a dot structure, the average value of the longest length within the cross section of the dot structure on the diffusion element layer surface (referred to as the average length of the dot structure) can be 0.1 to 50 μm. The average width of the groove structure and the average length of the uneven structure can be determined by randomly selecting 20 groove structures or uneven structures, taking scanning electron microscope images, measuring the lengths, and calculating the average of the 20.

[0046] The diffusion element layer (3) is made of a translucent material such as resin, glass, or nonwoven fabric, with a porous structure inside. The porous structure can be achieved by heating and melting resin or glass, then solidifying it while injecting gas, thereby forming bubbles inside. The porous structure may be composed of independent pores (independent pores), a connected structure in which independent pores are connected, or a combination of these. The porous structure may also reach the surface of the diffusion element layer. Nonwoven fabric is made by assembling fibers without weaving them together, and the voids between the fibers can be considered to be the porous structure.

[0047] When using resin or glass, the average diameter of the closed pores forming the porous structure or the individual pores forming the interconnected structure can be appropriately selected as long as the haze when formed into a diffusion element layer is 40% to 95% and the total light transmittance is 30% to 88%, and an example is 0.1 to 500 μm. The average diameter of the individual pores forming the closed pores or interconnected structure can be determined by cutting the resin or glass having a porous structure, randomly selecting 20 individual pores forming the closed pores or interconnected structure from the cross section, photographing them with a scanning microscope, measuring their diameters, and calculating the average of the 20 diameters.

[0048] When a nonwoven fabric is used, it can be appropriately selected as long as the haze of the diffusion element layer is 40% or more and 95% or less and the total light transmittance is 30% or more and 88% or less. For example, a nonwoven fabric having a basis weight of 5 to 30 g / m2 produced by wet papermaking using fibers with a fiber diameter of 3 to 20 μm and a fiber length of 0.1 to 2 mm can be used. 2 Examples of nonwoven fabrics include the following:

[0049] The material of the diffusion element layer (3) is not particularly limited as long as it does not impair the effects of the present invention, but examples thereof include polycarbonate resin; (meth)acrylic resin; polystyrene resin; polyolefin resin; polyester resin such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, and terebutylene terephthalate; various types of glass; glass fiber nonwoven fabric, polyolefin resin fiber nonwoven fabric such as polypropylene fiber; and the like.

[0050] The diffusion element layer (4) is made of a translucent material such as resin, glass, or nonwoven fabric, and has a plurality of through holes or non-through holes extending from one surface to the other. Furthermore, nonwoven fabric has voids that communicate from one surface to the other. That is, the voids in the nonwoven fabric can be treated as through holes, but the through holes in the diffusion element layer (4) refer to through holes that are different from the voids in the nonwoven fabric and are created by processing the nonwoven fabric.

[0051] The shapes of the through holes and non-penetrating holes are not particularly limited, and the cross-sectional shape on the surface of the diffusion element layer may be any of circular, elliptical, polygonal, etc. The average diameter of the through holes and non-penetrating holes can be appropriately selected as long as the resulting diffusion element layer has a haze of 40% to 95% and a total light transmittance of 30% to 88%, and an example is 0.1 to 50 μm. The average diameter of the through holes and non-penetrating holes can be determined by randomly selecting 20 through holes and non-penetrating holes, photographing them with a scanning microscope, measuring their diameters, and calculating the average of the 20. As mentioned above, for nonwoven fabrics, the measurement is not of the size of the through holes as voids, but of only the through holes created by processing, etc.

[0052] The material of the diffusion element layer (4) is not particularly limited as long as it does not impair the effects of the present invention, but examples thereof include polycarbonate resin; (meth)acrylic resin; polystyrene resin; polyolefin resin; polyester resin such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, and terebutylene terephthalate; various types of glass; glass fiber nonwoven fabric, polyolefin resin fiber nonwoven fabric such as polypropylene fiber; and the like.

[0053] The through holes and non-through holes in the diffusion element layer (4) can be formed by a known method such as a laser processing method.

[0054] The diffusion element layer (5) may be formed of a resin having multiple regions (e.g., cylindrical regions) with different refractive indices. These may be used alone or in combination. Examples of such a diffusion element layer (5) include a pillar structure disclosed in International Publication WO2015 / 111523 and a louver structure disclosed in Japanese Patent Application Laid-Open No. 2015-127819.

[0055] Of these diffusion element layers (1) to (5), a diffusion film having dispersed therein fine particles, a diffusion adhesive layer having dispersed therein fine particles, a nonwoven fabric having dispersed therein fine particles, a diffusion film having an uneven surface, and a porous film are preferred from the viewpoints of productivity and cost.

[0056] These diffusion element layers (1) to (5) can be colored with white or other color pigments or dyes, which makes it easy to adjust the seamlessness between the display and white or light-colored display peripheral components.

[0057] The haze of the diffusion element layer is not particularly limited as long as it does not impair the effects of the present invention, but is preferably 40% to 95%, more preferably 50% to 94%, and even more preferably 80% to 92%. When the haze is within this range, the diffusion and reflectivity are increased, resulting in a higher whiteness and a clearer image on the display. The haze of the diffusion element layer is determined by the method described in JIS K7136:2000, "Method for determining the haze of plastics - transparent materials."

[0058] The total light transmittance of the diffusion element layer is not particularly limited as long as it does not impair the effects of the present invention, but is preferably 30% to 88%, more preferably 40% to 80%, and even more preferably 50% to 70%. When the total light transmittance is within this range, the clarity of the display image is high, and the excellent diffusion and reflectivity result in a high whiteness and a seamless appearance.

[0059] <Other layers (a)> The optical film laminate of the present invention may include another layer (a). The reflective polarizer layer and the diffusing element layer may be laminated via the other layer (a).

[0060] The other layer (a) is not particularly limited, but may be a pressure-sensitive adhesive layer, an adhesive layer, a gap layer, a retardation film, a color filter, a layer printed with a pattern or design, or a film containing such a print. Here, the gap layer refers to a gap spaced apart. The other layer (a) can be colored with white or other color pigments or dyes. This allows for easy adjustment of seamlessness between the display and white or light-colored display peripheral components. Furthermore, seamlessness between the display and peripheral components can be easily adjusted using patterns or designs.

[0061] <Outermost layer on the visible side> When the optical film laminate is used in a display, the outermost surface layer may be used on the outermost surface on the viewing side, that is, on the surface of the diffusion element layer of the optical film laminate.

[0062] The outermost surface layer is not particularly limited, and may be, for example, a layer printed with a pattern or design, a film including such a print, etc. When a display using the optical film laminate is embedded in a material that uses white or a light color, such as an automobile or a house, seamlessness can be further improved if the outermost surface layer has the same color or pattern as the surrounding material of the display.

[0063] <<Characteristics of optical film laminates>> The transmitted light (T1) obtained by light from a C light source incident on the reflective polarizer layer side of the optical film laminate and exiting on the diffusion element layer side of the optical film laminate is measured according to JIS Z8722:2009, and the transmission Y value calculated using the C light source is not particularly limited as long as the effects of the present invention are not impaired, and can be 20 to 50, preferably 20 to 35 (see FIG. 3(a)). When the Y value of T1 is within this range, the brightness (visibility) is excellent and sufficient whiteness can be obtained, resulting in a display that can be seamlessly integrated with white or light-colored display peripheral components.

[0064] The reflected light (R1) obtained by measuring the reflected light (R1) from the C light source incident on the diffusion element layer side of the optical film laminate, reflecting off the optical film laminate, and emitting to the diffusion element layer side according to JIS Z8722:2009 is calculated using the C light source. The reflected Y value is not particularly limited as long as it does not impair the effects of the present invention, and can be 40 to 80, preferably 50 to 80, and more preferably 55 to 75 (see FIG. 3(b)). When the Y value of R1 is within this range, appropriate diffusion is obtained, resulting in excellent screen clarity and sufficient whiteness, making it possible to obtain a display that can be seamlessly integrated with white or light-colored display peripheral components.

[0065] Here, the Y value indicates the luminous reflectance (or luminous transmittance), and is calculated using the method described in JIS Z8722:2009 "Methods for measuring color - Reflected and transmitted object color" after measurement using the method described in JIS Z8722:2009 "Methods for measuring color - Reflected and transmitted object color." Illuminant C refers to auxiliary illuminant C specified in JIS Z8720:2012 "Standard illuminants (standard light) and standard light sources for colorimetry."

[0066] The optical film laminate of the present invention can have a whiteness WI value of 45 to 90, preferably 55 to 90, and more preferably 70 to 90, when measured using a spectrophotometer with a D65 light source and a specular elimination method (SCE). Here, the D65 light source refers to the standard illuminant D65 specified in JIS Z8720:2012, "Standard Illuminants (Standard Light) and Standard Illuminants for Colorimetry." The specular elimination method (SCE) refers to a method of measuring only the diffused light contained in the reflected light. The whiteness WI value is a numerical value specified in ASTM E313-73, and indicates the degree of whiteness. When the whiteness WI value of the optical film laminate is within this range, the film exhibits appropriate diffusivity, providing excellent visibility. Furthermore, the film exhibits sufficient whiteness, enabling a display to be seamlessly integrated with white or light-colored display peripheral components.

[0067] The whiteness WI of the optical film laminate of the present invention can be measured by the method described in ASTM E313-73. In the present invention, the whiteness WI was measured using a spectrophotometer (CM-700D manufactured by Konica Minolta) by SCE, which does not include the specular reflection component of a D65 light source.

[0068] <<Method of manufacturing optical film laminate>> The optical film laminate of the present invention can be produced by laminating a reflective polarizer layer and a diffusion element layer directly or via another layer (a). For example, when a pressure-sensitive adhesive layer is used as the other layer (a), the pressure-sensitive adhesive is first applied to a release film to form a pressure-sensitive adhesive layer, and the pressure-sensitive adhesive layer is then placed on the reflective polarizer layer and heat-laminated to form the laminate. After removing the release film from the resulting laminate, the diffusion element layer is placed on the pressure-sensitive adhesive layer and heat-laminated to obtain an optical film laminate. Heat lamination can be performed using a known laminator.

[0069] <<Applications of optical film laminates>> The optical film laminate of the present invention is an optical film laminate for displays, and is used by being laminated directly or indirectly with a polarizing plate (A). The display of the present invention is particularly used for displays such as display panels for automobiles, display panels for home appliances, and liquid crystal displays, organic EL displays, and micro LED displays embedded in the walls, floors, and ceilings of furniture and buildings.

[0070] The display according to the present invention may include a polarizing plate (A) (display (D1)) or may not include one (display (D2)).

[0071] <Polarizing plate (A)> The polarizing plate (A) is a plate that allows only light polarized or polarized in a specific direction to pass through. Any known polarizing plate can be used as the polarizing plate (A), and is not particularly limited as long as it does not impair the effects of the present invention. Polarizing plates generally used in displays can be used.

[0072] The polarizing plate (A) is disposed on the viewing side of the display panel device of the display.

[0073] Here, the polarizing plate (A) is (I) It can be used by being laminated facing the viewing side of a display panel device included in a display (i.e., when the polarizing plate (A) is included in a display, i.e., in the case of a display (D1)), (II) The polarizing plate (A) is not included on the viewing side of a display panel device included in a display (in the case of display (D2)), but can be laminated on the viewing side surface of the display, (III) The polarizing plate (A) is not included on the viewing side of a display panel device included in a display (in the case of display (D2)), but is laminated on the optical filter laminate of the present invention and can be used as a polarizing plate laminate, (IV) A polarizing plate (polarizing plate (B) different from polarizing plate (A)) is provided on the viewing side of the display panel device of the display, and the polarizing plate (B) can be further laminated on the viewing side surface of the display, (V) A polarizing plate (polarizing plate (B) different from polarizing plate (A)) is provided on the viewing side of the display panel device of the display, and is laminated on the optical filter laminate of the present invention, which can be used as a polarizing plate laminate. Here, the cases (I) to (III) are preferable in that they provide a display that has excellent visibility and can be seamless with the surrounding materials of the display that use white or light colors. The polarizing plate (B) may be the same as or different from the polarizing plate (A), and they are used by being arranged so that their transmission axes are oriented at 0±30° or 180±30°.

[0074] In the above cases (I) to (V), the polarizing plate (A) is laminated directly or via another layer (b). The other layer (b) is not particularly limited, but may be a pressure-sensitive adhesive layer, an adhesive layer, or the like. The other layer (b) may be colored with a white or other color pigment or dye. This facilitates seamless integration of the display with white or light-colored display peripheral components.

[0075] <Arrangement of Optical Film Laminate> The optical film laminate of the present invention is disposed in a display on the viewing side of the polarizing plate (A) directly or via another layer (c) (see FIGS. 1 and 2). In this case, the optical film laminate is disposed so that the diffusion element layer of the optical film laminate is closer to the viewing side than the reflective polarizer layer (see FIGS. 1 and 2). The other layer (c) is not particularly limited, but may be a pressure-sensitive adhesive layer, an adhesive layer, a retardation film, a color filter, or the like. The other layer (c) may be colored with a white or other color pigment or dye. This facilitates seamless integration of the display with white or light-colored display peripheral components.

[0076] When the optical film laminate of the present invention is arranged, the optical film laminate is arranged so that the transmission axis of the reflective polarizer of the optical film laminate and the transmission axis of the polarizing plate (A) form an angle of 0±30° or 180±30°. Polarized light orthogonal to the transmission axis of the polarizing plate (A) is reflected by the reflective polarizer layer.

[0077] By arranging the optical film laminate as described above, the following effects can be achieved. Specifically, light emitted from a liquid crystal panel or an organic EL panel is converted into transmitted polarized light by the polarizing plate (A) located on the viewing side. By aligning the transmission axis of the reflective polarizer layer of the optical film laminate of the present invention with the transmission axis of the polarizing plate (A) located on the viewing side of the display in a direction of 0±30° or 180±30°, the reflective polarizer layer (1) suppresses a decrease in the transmittance of light emitted from the polarizing plate (A) and (2) enables ambient light and diffused light from the diffusion element layer to be reflected to the reflective polarizer layer. The interaction between this reflected light and the diffused light generated by the diffusion element layer from the reflected light (3) increases the white brightness of the display while maintaining good visibility, thereby achieving seamless white display.

[0078] <Polarizing plate laminate in the cases (III) and (V)> As described above, the optical film laminate of the present invention can be used as a polarizing plate laminate by laminating it with a polarizing plate (A) (see FIG. 2).

[0079] The polarizing plate laminate is laminated to the reflective polarizer layer of the optical film laminate on the side opposite to the diffusion element layer of the optical film laminate, either directly or via another layer (b) (see FIG. 2).

[0080] The polarizing plate (A) of the polarizing plate laminate and the reflective polarizer layer are arranged so that their transmission axes form a relationship of 0±30° or 180±30°.

[0081] The transmitted light (T2) of the light from a C light source incident on the polarizing plate side of the polarizing plate laminate and emitted to the diffusion element layer side of the polarizing plate laminate is measured according to JIS Z8722:2009. The transmission Y value calculated using the C light source is not particularly limited as long as it does not impair the effects of the present invention, and can be 15 to 40, preferably 20 to 40, and more preferably 25 to 40 (see FIG. 4(a)). When the Y value of T2 is within this range, the brightness (visibility) is excellent and sufficient whiteness can be obtained, making it possible to obtain a display that can be seamlessly integrated with white or light-colored display peripheral components.

[0082] The reflected light (R2) obtained by measuring the reflected light (R2) from the C light source incident on the diffusion element layer side of the polarizer laminate, reflecting off the polarizer laminate, and emitting to the diffusion element layer side according to JIS Z8722:2009 is calculated using the C light source. The reflected Y value is not particularly limited as long as it does not impair the effects of the present invention, and can be 40 to 80, preferably 50 to 80, and more preferably 65 to 80 (see FIG. 4(b)). When the Y value of R1 is within this range, appropriate diffusion is obtained, resulting in excellent screen clarity and sufficient whiteness, making it possible to obtain a display that can be seamlessly integrated with white or light-colored display peripheral components.

[0083] Here, the Y value indicates the luminous reflectance (or luminous transmittance), and is calculated using the method described in JIS Z8722:2009 "Methods for measuring color - Reflected and transmitted object color" after measurement using the method described in JIS Z8722:2009 "Methods for measuring color - Reflected and transmitted object color." Illuminant C refers to auxiliary illuminant C specified in JIS Z8720:2012 "Standard illuminants (standard light) and standard light sources for colorimetry."

[0084] The polarizing plate laminate of the present invention can have a whiteness WI value of 45 to 90, preferably 55 to 90, and more preferably 70 to 90, when measured using a spectrophotometer with a D65 light source and a specular elimination method (SCE). Here, the D65 light source refers to the standard illuminant D65 specified in JIS Z8720:2012, "Standard Illuminants (Standard Light) and Standard Illuminants for Colorimetry." The specular elimination method (SCE) refers to a method of measuring only the diffused light contained in the reflected light. The whiteness WI value is a numerical value specified in ASTM E313-73, and indicates the degree of whiteness. When the whiteness WI value of the optical film laminate is within this range, the film has adequate diffusion properties, resulting in excellent visibility. Furthermore, sufficient whiteness can be achieved, resulting in a display that can be seamlessly integrated with white or light-colored display peripheral components.

[0085] The whiteness WI of the polarizing plate laminate of the present invention can be measured by the method described in ASTM E313-73. In the present invention, the whiteness WI was measured using a spectrophotometer (CM-700D manufactured by Konica Minolta) by SCE, which does not include the specular reflection component of a D65 light source.

[0086] The polarizing plate laminate of the present invention can be produced by laminating the optical film laminate directly or via another layer (d). The other layer (d) is not particularly limited, and examples thereof include a pressure-sensitive adhesive layer, an adhesive layer, a retardation film, a color filter, and the like. The other layer (d) can be colored using a white or other color pigment or dye. This facilitates seamless integration between the display and white or light-colored display peripheral components. For example, when a pressure-sensitive adhesive layer is used as the other layer (d), the pressure-sensitive adhesive is first coated on a release film to form a pressure-sensitive adhesive layer, which is then overlaid on the optical film laminate and heat-laminated. After removing the release film from the resulting laminate, a polarizing plate (A) is overlaid on the pressure-sensitive adhesive layer and heat-laminated to obtain a polarizing plate laminate. Heat-lamination can be performed using a known laminator. [Example]

[0087] Next, the present invention will be explained in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples in any way.

[0088] <Preparation of Optical Film Laminate> Examples 1 to 7 An acrylic resin paint containing dispersed titanium oxide microparticles was applied to the treated surface of a 100 μm thick transparent PET film (Cosmoshine A4301, manufactured by Toyobo Co., Ltd.) and dried to obtain diffusion element layers 1 to 7 with PET film having a specific haze and a specific total light transmittance. The haze and total light transmittance of the diffusion element layer were adjusted by adjusting the amount of titanium oxide fine particles and the thickness of the diffusion element layer. Next, for each of the diffusion element layers 1 to 7 with PET film, a reflective polarizer made of a multilayer polymer stretched film (APF-V3, manufactured by 3M) was attached to the diffusion element layers 1 to 6, and a reflective polarizer made of a metal nanowire grid (WGF, manufactured by Asahi Kasei Corporation) was attached to the diffusion element layer 7 via a 25 μm acrylic transparent adhesive (TD06A, manufactured by Tomoegawa Paper Co., Ltd.), thereby obtaining optical film laminates 1 to 7 of Examples 1 to 7. Table 1 shows the materials used in the diffusion element layer, the haze, and the total light transmittance, as well as the materials used in the reflective polarizer layer and the total light transmittance of the optical film laminate.

[0089] Example 8 An acrylic adhesive (TD06D92, manufactured by Tomoegawa Paper Co., Ltd.) with a thickness of 25 μm, a haze of 92%, and a total light transmittance of 40% and containing dispersed titanium oxide microparticles was used as the diffusion element layer 8, and this diffusion element layer was bonded between a reflective polarizer (APF-V3, manufactured by 3M Co., Ltd.) made of a multilayer polymer stretched film and the treated surface of a 100 μm thick transparent PET film (Cosmoshine A4301, manufactured by Toyobo Co., Ltd.) to obtain the optical film laminate 8 of Example 8. The haze and total light transmittance of the diffusion element layer were adjusted by adjusting the amount of titanium oxide fine particles and the thickness of the diffusion element layer. Table 1 shows the materials used in the diffusion element layer, the haze and total light transmittance values, the materials used in the reflective polarizer layer, and the total light transmittance of the optical film laminate.

[0090] Example 9 The diffusion element layer 9 was a diffusion film (LCF, SO16, manufactured by Tomoegawa Paper Co., Ltd.) with a haze of 92% and a total light transmittance of 85%, which had multiple cylindrical regions with different refractive indices formed inside a transparent resin.This diffusion element layer was bonded to a reflective polarizer (APF-V3, manufactured by 3M Co., Ltd.) made of a multilayer polymer stretched film via a 25 μm acrylic transparent adhesive (TD06A, manufactured by Tomoegawa Paper Co., Ltd.), thereby obtaining the optical film laminate 9 of Example 9. Table 1 shows the materials used in the diffusion element layer, the haze and total light transmittance values, the materials used in the reflective polarizer layer, and the total light transmittance of the optical film laminate.

[0091] Example 10 The diffusion element layer 10 was a diffusion film (Yupo Illumination Paper BCR, manufactured by Yupo Corporation) with a porous interior and a haze of 92% and a total light transmittance of 51%, and this diffusion element layer was bonded to a reflective polarizer (APF-V3, manufactured by 3M) made of a multilayer polymer stretched film via a 25 μm acrylic transparent adhesive (TD06A, manufactured by Tomoegawa Paper Co., Ltd.), thereby obtaining the optical film laminate 10 of Example 10. Table 1 shows the materials used in the diffusion element layer, the haze and total light transmittance values, the materials used in the reflective polarizer layer, and the total light transmittance of the optical film laminate.

[0092] Example 11 The diffusion element layer 11 was a diffusion film (High Tier Yupo WSF, manufactured by Yupo Corporation) that was a composite of a film with pores inside the resin and a nonwoven fabric, and had a haze of 95% and a total light transmittance of 31%.This diffusion element layer was bonded to a reflective polarizer (APF-V3, manufactured by 3M) made of a multilayer polymer stretched film via a 25 μm acrylic transparent adhesive (TD06A, manufactured by Tomoegawa Paper Co., Ltd.), thereby obtaining the optical film laminate 11 of Example 11. Table 1 shows the materials used in the diffusion element layer, the haze and total light transmittance values, the materials used in the reflective polarizer layer, and the total light transmittance of the optical film laminate.

[0093] Example 12 The acrylic resin paint containing dispersed titanium oxide microparticles used in Example 4 was applied to the surface of a reflective polarizer (APF-V3, manufactured by 3M) consisting of a multilayer polymer stretched film and dried to obtain an optical film laminate 12 of the present invention in which a diffusion element layer 12 was provided directly on the surface of the reflective polarizer. To confirm the optical properties of this diffusion element layer 12, the acrylic resin paint was applied to the treated surface of a 100 μm thick transparent PET film (Cosmoshine A4301, manufactured by Toyobo Co., Ltd.) under the same conditions as those used to prepare the diffusion element 12 of this embodiment, and the resulting diffusion element layer with PET film after drying had a haze of 92% and a total light transmittance of 50%. The materials used in the diffusion element layer, the haze (value with the above-mentioned PET film), the total light transmittance (value with the above-mentioned PET film), the materials used in the reflective polarizer layer, and the total light transmittance of the optical film laminate are summarized in Table 1.

[0094] <Preparation of Optical Film Laminate, Diffusion Element Layer, and Reflective Polarizer Layer of Comparative Examples> (Comparative Example 1) An acrylic resin paint containing dispersed silicone microparticles was applied to the treated surface of a 100 μm thick transparent PET film (Cosmoshine A4301, manufactured by Toyobo Co., Ltd.) and dried to obtain a diffusion element layer a of Comparative Example 1 with a haze of 25% and a total light transmittance of 90%. The haze and total light transmittance of the diffusion layer were adjusted by adjusting the amount of silicone microparticles and the thickness of the diffusion layer. The materials used for the diffusion layer, as well as the haze and total light transmittance, are summarized in Table 1.

[0095] (Comparative Examples 2 to 4) An acrylic resin paint containing dispersed titanium oxide microparticles was applied to the treated surface of a 100 μm thick transparent PET film (Cosmoshine A4301, manufactured by Toyobo Co., Ltd.) and dried to obtain diffusion element layers b to d with PET film having a specific haze and a specific total light transmittance. The haze and total light transmittance of the diffusion element layer were adjusted by adjusting the amount of titanium oxide fine particles and the thickness of the diffusion element layer. Next, an Al vapor-deposited film (total light transmittance 50%) was attached to the diffusion element layer d with the PET film via a 25 μm acrylic transparent adhesive (TD06A, manufactured by Tomoegawa Paper Co., Ltd.) to obtain the optical film laminate d of Comparative Example 4. Table 1 shows the materials used in the diffusion element layer, the haze, and the total light transmittance, as well as the materials used in the reflective polarizer layer and the total light transmittance of the optical film laminate.

[0096] (Comparative Example 5) The reflective polarizer V3 of Comparative Example 5 was prepared using only a reflective polarizer made of a multilayer stretched polymer film (APF-V3, manufactured by 3M). The materials used in the reflective polarizer layer and their total light transmittances are summarized in Table 1.

[0097] Examples 1 to 12 and Comparative Examples 1 to 5 are summarized in Table 1. [Table 1]

[0098] <Preparation of Polarizing Plate Laminate Using Optical Film Laminate> Example 13 A polarizing plate (polarization degree 99.9%, transmittance 42%) was attached to the reflective polarizer side surface of the optical film laminate 4 produced in Example 4 via a 25 μm acrylic transparent adhesive (TD06A, manufactured by Tomoegawa Paper Co., Ltd.), to obtain a polarizing plate laminate 13 of Example 13. The polarizing plate was attached such that the transmission axis of the polarizing plate was shifted by 15° with respect to the transmission axis of the reflective polarizer.

[0099] Example 14 A polarizing plate laminate 14 of Example 14 was obtained in the same manner as in Example 13, except that the transmission axis of the polarizing plate was shifted by 30° with respect to the transmission axis of the reflective polarizer of the optical film laminate.

[0100] (Comparative Example 6) A polarizing plate laminate e of Comparative Example 6 was obtained in the same manner as in Example 13, except that the transmission axis of the polarizing plate was shifted by 45° with respect to the transmission axis of the reflective polarizer of the optical film laminate.

[0101] (Comparative Example 7) A polarizing plate (polarization degree 99.9%, transmittance 42%) was attached to the surface of the optical film laminate 4 produced in Example 4 on the diffusion element layer side via a 25 μm acrylic transparent adhesive (TD06A, manufactured by Tomoegawa Paper Co., Ltd.), thereby obtaining a polarizing plate laminate f of Comparative Example 7. The polarizing plate was attached so that the transmission axis of the reflective polarizer and the transmission axis of the polarizing plate were oriented at 0°.

[0102] Examples 13 and 14 and Comparative Examples 6 and 7 are summarized in Table 2. [Table 2]

[0103] <Measurement> (Total light transmittance and haze measurements) The total light transmittance and haze of the diffusion element layer and the optical film laminate were measured using a haze meter (NDH-2000, manufactured by Nippon Denshoku Industries Co., Ltd.), with the total light transmittance measured in accordance with JIS K7361-1:1997 and the haze measured in accordance with JIS K7136:2000. The haze of the diffusion element layer was measured using a sample in which a transparent PET film (Cosmoshine A4301, manufactured by Toyobo Co., Ltd.) was attached to one side of the diffusion element layer.

[0104] (Measurement of transmitted Y value and reflected Y value) Measurements of the transmission Y value and reflection Y value of each optical film laminate of Examples 1 to 12 and Comparative Example 4, each diffusion element layer of Comparative Examples 1 to 3, and the reflective polarizer layer of Comparative Example 5 were carried out using a spectrophotometer (Shimadzu Corporation, UV-2500) at a 2° field of view.

[0105] In the case of an optical film laminate, the transmitted light (T1) formed by light from a C light source incident on the reflective polarizer layer side of the optical film laminate and exiting on the diffusion element layer side of the optical film laminate was measured according to JIS Z8722:2009, and the value calculated using the C light source was designated the transmission Y value. In the case of a diffusion element layer, the transmitted light formed by light from a C light source incident on one side of the diffusion element layer, passing through the diffusion element layer and exiting from the other side was measured. In the case of a reflective polarizer layer, the transmitted light formed by light from a C light source incident on one side of the reflective polarizer layer, passing through the reflective polarizer layer and exiting from the other side was measured according to JIS Z8722:2009, and the value calculated using the C light source was designated the transmission Y value.

[0106] In the case of an optical film laminate, the reflected light (R1) formed when light from a C light source incident on the diffusion element layer side of the optical film laminate is reflected by the optical film laminate and emitted toward the diffusion element layer side; in the case of a diffusion element layer, the reflected light formed when light from a C light source incident on one side of the diffusion element layer is reflected within the diffusion element layer and emitted toward one side of the diffusion element layer; and in the case of a reflective polarizer layer, the reflected light formed when light from a C light source incident on one side of the reflective polarizer layer is reflected within the reflective polarizer layer and emitted toward one side of the reflective polarizer layer, were measured according to JIS Z8722:2009, and the value calculated using the C light source was designated the reflection Y value.

[0107] However, since the optical film laminate and the reflective polarizer layer have a transmission axis, it is necessary to eliminate the influence of their polarization. Therefore, in this measurement, for all examples and comparative examples, when the light source is incident on the evaluation sample, in the case of a sample using an optical film laminate or a reflective polarizer layer, the azimuth angle was first set to 0° based on the transmission axis direction of the sample, and the average values ​​of the measured value at that time and the measured value when the azimuth angle was rotated 90° based on that were calculated, and were used as the transmission Y value and the reflection Y value of the evaluation sample. In addition, in the case of a diffusion element layer, since it does not have a transmission axis, an arbitrary evaluation sample arrangement was set to an azimuth angle of 0°, and the average values ​​of the measured values ​​when the azimuth angle was rotated 90° based on that were calculated, and were used as the transmission Y value and the reflection Y value of the evaluation sample.

[0108] (Measurement of transmission Y value and reflection Y value when combined with a polarizing plate) The optical film laminates of Examples 1 to 12 and Comparative Example 4, the diffusion element layers of Comparative Examples 1 to 3, and the reflective polarizer layer of Comparative Example 5 were bonded to a polarizing plate (polarization degree 99.9%, transmittance 42%) via a 25 μm acrylic transparent adhesive (TD06A, manufactured by Tomoegawa Paper Co., Ltd.), and the transmission Y values ​​and reflection Y values ​​of the polarizing plate laminate, polarizing plate diffusion element layer, and polarizing plate reflective polarizer layer were measured using a spectrophotometer (UV-2500, manufactured by Shimadzu Corporation) at a 2° field of view. In the case of samples using a reflective polarizer layer, the polarizing plate was bonded so that the transmission axis of the reflective polarizer was aligned with the transmission axis of the polarizing plate (0° or 180°).

[0109] In the case of a sample using an optical film laminate, the transmission Y value was measured by measuring the transmitted light (T2) of light from a C light source incident from the polarizing plate side of the polarizing plate laminate and emitted to the diffusion element layer side of the polarizing plate laminate; in the case of a sample using a diffusion element layer, the transmitted light of light from a C light source incident from the polarizing plate side of the polarizing plate diffusion element layer and transmitted through the polarizing plate diffusion element layer and emitted to the diffusion element layer side of the polarizing plate diffusion element layer; and in the case of a sample using a reflective polarizer layer, the transmitted light of light from a C light source incident from the polarizing plate side of the polarizing plate reflective polarizer layer and transmitted through the reflective polarizer layer and emitted to the reflective polarizer layer side of the polarizing plate reflective polarizer layer, according to JIS Z8722:2009, and the value calculated using the C light source was taken as the transmission Y value.

[0110] In the case of a sample using an optical film laminate, the reflected light (R1) formed by light from a C light source incident on the diffusion element layer side of the polarizing plate laminate, being reflected by the polarizing plate laminate, and emerging on the diffusion element layer side was measured according to JIS Z8722:2009. In the case of a sample using a diffusion element layer, the reflected light formed by light from a C light source incident on the diffusion element layer side of the polarizing plate diffusion element layer, being reflected within the diffusion polarizer of the polarizing plate diffusion element layer, passing through the polarizing plate diffusion element layer, and emerging on the diffusion element layer side was measured. In the case of a sample using a reflective polarizer layer, the reflected light formed by light from a C light source incident on the reflective polarizer layer side of the polarizing plate reflective polarizer layer, being reflected within the reflective polarizer layer of the polarizing plate reflective polarizer layer, and passing through the polarizing plate reflective polarizer layer, and emerging on the reflective polarizer layer side was measured, and the value calculated using the C light source was used as the reflection Y value.

[0111] However, since the optical film laminate and the reflective polarizer layer have a transmission axis, it is necessary to eliminate the influence of their polarization. Therefore, in this measurement, for all examples and comparative examples in which a polarizing plate was bonded, when the light source was incident on the evaluation sample, in the case of a sample using an optical film laminate or a reflective polarizer layer, first, the azimuth angle was set to 0° based on the transmission axis direction of the samples, and the average values ​​of the measured values ​​at that time and the measured values ​​when the azimuth angle was rotated 90° based on that were calculated, and were used as the transmission Y value and the reflection Y value of the evaluation sample. In addition, in the case of a diffusion element layer, since it does not have a transmission axis, an arbitrary evaluation sample arrangement was set to an azimuth angle of 0°, and the average values ​​of the measured values ​​when the azimuth angle was rotated 90° based on that were calculated, and were used as the transmission Y value and the reflection Y value of the evaluation sample.

[0112] (Measurement of whiteness) For each of the optical film laminates of Examples 1 to 12 and Comparative Example 4, the diffusion element layers of Comparative Examples 1 to 3, and the reflective polarizer layer of Comparative Example 5, a black PET film with a transmittance of 0% was attached to the reflective polarizer surface of the optical film laminate, one surface of the diffusion element layer of the diffusion element layer, and one surface of the reflective polarizer layer of the reflective polarizer layer via a 25 μm acrylic transparent adhesive (TD06A, manufactured by Tomoegawa Paper Co., Ltd.), and the whiteness was measured from the diffusion element side of the optical film laminate and the diffusion element layer, and from the reflective polarizer layer side of the reflective polarizer layer. Measurements were performed using a spectrophotometer (CM-700D, manufactured by Konica Minolta, Inc.) in SCE mode with a D65 light source to determine the whiteness (WI) (in accordance with ASTM E313-73 standard).

[0113] However, since the optical film laminate and the reflective polarizer layer have a transmission axis, it is necessary to eliminate the influence of their polarization. Therefore, in this measurement, for all examples and comparative examples in which a black PET film was bonded, when the light source was incident on the evaluation sample, in the case of a sample using an optical film laminate and a reflective polarizer layer, the measured values ​​when their transmission axes were perpendicular to the ground (referred to as an azimuth angle of 0°) and when the azimuth angle was rotated 90° from that were calculated, and the average values ​​of each measured value were calculated to obtain the transmission Y value and reflection Y value of the evaluation sample. In addition, in the case of a diffusion element layer, since it does not have a transmission axis, an arbitrary evaluation sample arrangement was set to an azimuth angle of 0°, and the average values ​​of each measured value when the azimuth angle was rotated 90° from that were calculated to obtain the whiteness WI value of the evaluation sample.

[0114] The transmission Y value, reflection Y value, and whiteness WI value of the structures based on each example are summarized in Table 3. [Table 3]

[0115] As can be seen from the results in Table 3, the polarizing plate laminates in which a polarizing plate was bonded to the optical film laminates of Examples 1 to 12 and the polarizing plate laminates of Examples 13 and 14 had a high transmission Y value of 15 or more, and also had a high reflection Y value of 40 or more.

[0116] Furthermore, the transmission Y value, which is an index of the brightness of the display, was higher than 20 in Examples 1 to 5, 7 to 10, and 12, and in particular, Examples 1 to 4, 9, and 12 achieved even higher values ​​of 25 or more, indicating that the display was bright and clear. In addition, the reflective Y value, which is an indicator of seamlessness, achieved higher values ​​of 50 or more in Examples 3 to 14, and particularly in Examples 4 to 6 and 10 to 12, achieving even higher values ​​of 65 or more, indicating that a seamless display was obtained.

[0117] With regard to whiteness, the higher the reflection Y value, the higher the whiteness WI value, and in this example, a whiteness WI value of 45 or more was obtained. Furthermore, in Examples 3 to 14, even higher values ​​of 55 or more were obtained, and in particular, in Examples 4 to 6 and 11 to 14, even higher values ​​of 70 or more were obtained.

[0118] Therefore, when the optical film laminate of this example was used in a display, it was possible to increase all of the values ​​of the transmission Y value, reflection Y value, and whiteness WI value. Among them, the optical film laminates of Examples 3 to 5, 7 to 10, and 12 were able to increase all of the values ​​of the transmission Y value, reflection Y value, and whiteness WI value, and in particular, the optical film laminates of Examples 4 and 12 were able to further increase all of the values ​​of the transmission Y value, reflection Y value, and whiteness WI value.

[0119] When the optical film laminate of the present invention is used in a display, the transmission Y value and reflection Y value when the optical film laminate is combined with a polarizing plate are thought to determine the display characteristics and seamlessness of the display. As described above, the examples of the present invention have sufficiently high transmission Y values, which do not significantly impair brightness or clarity in terms of visibility when the display is turned on, and sufficiently high reflection Y values, which make it possible to achieve white or pale-colored seamlessness when the display is turned off, and are therefore thought to be able to achieve a good balance between display and seamlessness.

[0120] To prove the above, the optical film laminates of Examples 1, 4, 9, and 12 were attached to a display having a polarizing plate on the viewing side via a 25 μm acrylic transparent adhesive (TD06A, manufactured by Tomoegawa Paper Co., Ltd.) so that the transmission axis of the polarizing plate on the viewing side of the display and the transmission axis of the reflective polarizer layer of the optical film laminate were aligned in the same direction, and visibility was confirmed.

[0121] As a result, all of the displays having the optical film laminates exhibited good seamlessness when the display was turned off, and were able to sufficiently hide the presence of the display. Furthermore, when the display was turned on, all of the displays having the optical film laminates exhibited sufficient visibility, with images and text being bright enough to be clearly seen and with little blurring.

[0122] On the other hand, when Comparative Example 1 was attached to a polarizing plate, the transmittance Y value was as high as 43.1, but the whiteness WI value was as low as 19.6, less than half of that of this example, and the film was gray.

[0123] Furthermore, in Comparative Examples 2 to 4, the transmission Y value is so low that the images displayed on the display cannot be seen clearly.

[0124] Furthermore, Comparative Example 5 had the lowest whiteness WI value of 2.1, had a metallic luster, and reflected light like a mirror, so it was not possible to achieve seamless white or pale colors.

[0125] In Comparative Example 6, the transmission axes of the reflective polarizer layer and the polarizing plate were significantly misaligned at 45°, resulting in a low transmission Y value and poor visibility of the display, making it unsuitable for the present invention.

[0126] In addition, in Comparative Example 7, due to its relationship with the polarizing plate, the reflective polarizer layer is positioned on the viewer side. As a result, the whiteness WI value is very low at 2.3, and the film has a metallic luster and reflects like a mirror, making it impossible to achieve seamless white or light-colored images.

[0127] Furthermore, as in Examples 1, 4, 9, and 12, the optical film laminate of Comparative Example 4 was attached to a display having a polarizing plate on the viewing side via a 25 μm acrylic transparent adhesive (TD06A, manufactured by Tomoegawa Paper Co., Ltd.) so that the transmission axis of the polarizing plate on the viewing side of the display and the transmission axis of the reflective polarizer layer of the optical film laminate were in the same direction, and visibility was confirmed. As a result, when the display was turned off, the seamlessness was good and the presence of the display could be hidden, but when the display was turned on, the image was dark and the images and text were very blurred, making it difficult to see.

[0128] Although the present invention focuses on the whiteness WI value, it is also possible to color the product to match the hue of the surrounding area or to print a pattern or design to match the surrounding area. In this case, the whiteness WI value is not dependent on the product. [Explanation of symbols]

[0129] 10 Optical film laminate 11 Reflective polarizer layer 12 Diffusion element layer 20 Polarizing plate laminate 30C light source 100 Internal structure of the display (with polarizing plate (A)) 110 Display panel device (with polarizing plate (A)) 120 Display panel device (without polarizer (A)) 130 Polarizing plate (A) 200 Internal structure of the display (without polarizing plate (A))

Claims

1. A polarizing plate laminate including an optical film laminate in which a reflective polarizer layer and a diffusion element layer are laminated directly or via another layer (a), and a polarizing plate (A) arranged to face a viewing side of a display panel device included in a display, the diffusing element layer is disposed on the viewing side of the display panel device relative to the reflective polarizer layer; the optical film laminate is laminated on the viewing side of the polarizing plate (A) directly or via another layer (d), the optical film laminate is arranged so that the relationship between the transmission axis of the polarizing plate (A) and the transmission axis of the reflective polarizer layer is −30° to +30° or +150° to +210°, A polarizing plate laminate, characterized in that the reflective polarizer layer reflects polarized light perpendicular to the transmission axis of the polarizing plate (A), the haze of the diffusion element layer is 80% or more and 95% or less, and the total light transmittance of the diffusion element layer is 30% or more and 70% or less.

2. the reflective polarizer layer includes a first polymer layer and a second polymer layer; 2. The polarizing plate laminate according to claim 1, wherein either the first polymer layer or the second polymer layer is a naphthalate-based polymer.

3. 3. The polarizing plate laminate according to claim 1, wherein the diffusion element layer is any one of a diffusion film having fine particles dispersed therein, a diffusion adhesive layer having fine particles dispersed therein, a nonwoven fabric, a diffusion film having an uneven surface, and a porous film.

4. 4. The polarizing plate laminate according to claim 1, wherein the diffusion element layer has a total light transmittance of 30% or more and 70% or less.

5. The optical film laminate is transmitted light (T1) obtained by light from a C light source incident on the reflective polarizer layer side of the optical film laminate, passing through the optical film laminate and emitting on the diffusion element layer side of the optical film laminate is measured in a 2° visual field in accordance with JIS Z8722:2009, and then the transmission Y value calculated using a C light source is 20 or more and 50 or less; The polarizing plate laminate according to any one of claims 1 to 4, wherein the reflected light (R1) is light from a C light source incident on the diffusion element layer side of the optical film laminate, reflected by a reflective polarizer of the optical film laminate, transmitted through the optical film laminate to the diffusion element layer side, and emitted from the optical film laminate, and is measured at a 2° field of view in accordance with JIS Z8722:2009 standard, and the reflection Y value calculated using a C light source is 40 or more and 80 or less.

6. The polarizing plate laminate according to any one of claims 1 to 5, wherein the optical film laminate has a whiteness index (WI) value of 45 or more and 90 or less in a spectrophotometric colorimeter (SCE) using a D65 light source in accordance with ASTM E313-73 standard.

7. The polarizing plate laminate is transmitted light (T2) obtained by emitting light from a C light source incident on the polarizing plate side of the polarizing plate laminate, passing through the polarizing plate laminate, and emitting it on the diffusion element layer side of the polarizing plate laminate is measured in a 2° field of view in accordance with JIS Z8722:2009, and then the transmission Y value calculated using a C light source is 15 or more and 40 or less; 2. The polarizer laminate of claim 1, wherein the reflected light (R2) is light from a C light source incident on the diffusion element layer side of the polarizer laminate, reflected by a reflective polarizer of the polarizer laminate, transmitted through the polarizer laminate to the diffusion element layer side, and emitted from the polarizer laminate. After measuring the reflected light (R2) at a 2° field of view in accordance with JIS Z8722:2009, the reflection Y value calculated using a C light source is 40 or more and 80 or less.

8. A display (D1) having a laminate structure including a display panel device and the polarizer laminate according to any one of claims 1 to 7 on the viewing side of the display panel device, the polarizing plate (A) is laminated on the viewing side of a display panel device directly or via another layer (b), the optical film laminate is disposed such that the transmission axis of the polarizing plate (A) and the transmission axis of the reflective polarizer layer are oriented in a direction of −30° to +30° or +150° to +210°, A display characterized in that the reflective polarizer layer reflects polarized light that is orthogonal to the transmission axis of the polarizing plate (A).

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